Processes for the production of alkyl esters of monocarboxylic acids, e.g. ethyl acrylate, are well known in the art. Processes for such include direct esterification by reaction of an alkanol and the carboxylic acid as well as other processes such as those wherein esters of monounsaturated acids are produced by interacting the unsaturated acid with a monoolefin in the presence of sulfuric acid. Typical of such processes are those disclosed in U.S. Pat. No. 3,539,621 issued Nov. 10, 1970, to Cipollone et al. and U.S. Pat. No. 3,703,539 issued Nov. 21, 1972, to Di Liddo. Regardless of the process from which an ester is derived, the crude ester product will contain various light ends impurities which must be removed. Some of these light ends impurities are water soluble and some are water insoluble, with the particular impurities in any given crude ester depending on the method of production and purity of reactants. The various light ends impurities may be removed by conventional distillation; however, because of various possible azeotropes and mutual solubilities an excessively large distillation column is required in order to avoid product losses. Because of this, much time and effort is expended to discover new and useful methods for removing these light ends impurities.
It is thus an object of the present invention to provide a new and useful distillation process for removing light ends from crude alkyl esters of carboxylic acids. A particular object to the present invention is to provide a new and useful distillation method for efficiently removing light ends from a crude ethyl acrylate prepared by the interaction of ethylene and acrylic acid in the presence of sulfuric acid. Additional objects will become apparent from the following description of the following invention. In the following description and the claims, all parts and percentages are by weight unless otherwise specified.